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Creating innovative mechanical designs is hard (I should know—I do it for a living). Sometimes, you’re pushed to the very limit to imagine a concept or mechanism that could actually work. At times like this, manufacturing is a distant utopia that we can only hope to reach, so we ignore it. But, at the end of the day, we’re only fooling ourselves if we dream up uneconomical designs. The most brilliant machine ever conceived is nothing if it doesn’t make financial sense to produce and operate. For example, why aren’t water desalination, electric cars, and solar photovoltaics more prevalent? Why are we thirsty in the middle of an ocean, making tiny explosions to turn wheels, and drilling for oil when the sun shines all day? Because all ideas are subject to the constraints of available technology, and the benefits must always outweigh the costs. Just because something is possible does not mean it is economical.
在基于“增大化现实”技术e often many ways to perform the same exact task, each with different制造成本. As designers and engineers, it’s our job to find the least expensive ways to design for manufacturing. To that end, here are some practical tips to increase your manufacturing efficiency through design.
Manufacturing Efficiency
Manufacturing is all about efficiency. This is achieved through specialization—the more dedicated a tool or process is, the better and faster it generally is. Generally speaking, versatility comes at the cost of specialization. Humans, being very versatile creatures, are usually not the best factory workers: We take time to train; we’re slow; we need breaks; and we make mistakes. That’s why we turn to customized machinery to replace human labor—it’s overwhelmingly faster, more precise, and longer-lasting.
Of course, creating dedicated tooling and machinery requires up-front human labor. The cost of custom tooling must be weighed against its long-term gains. This is why it can be useful to amortize tooling cost into a “piece price” (price per unit) in the pursuit of calculating the time it takes to achieve ROI (return on investment). Naturally, production volumes are central to this equation—if you’re going to crank out millions of widgets a year, your customized tooling will pay for itself. This is common in the automotive industry. On the other hand, manual manufacturing processes can make more sense than customized tooling for low-volume production. For example, sailboat and airplanes are largely assembled by hand. These are all commercial decisions driven by the free market. Designers and engineers must have their company’s financial abilities and expectations clearly communicated, so that they’re able to make prudent manufacturing decisions.
制作与购买
一个极具吸引力的，最畅销的方法是使用现成的解决方案。换句话说，不要重新发明轮子！由于资本主义，发明者和创新者提供了绝对丰富的预制零件，到了几乎可以用厨师制作三明治的方式设计产品。为什么有屠夫可以为您做屠夫时杀死牛，比以往任何时候都更快更便宜？同样，购买预先制造的组件通常会更有意义，而不是自己设计它们。这对螺栓，轴承，电动机等直观。其他类别，如齿轮和外壳，可以是一个折腾，因为对自定义的需求开始超过现成的东西。请记住，下次发现自己涉及未知的设计领土机会，其他人已经提供预先制定的解决方案（谷歌是您的朋友）。
Manufacturing methods
There’s more than one way to skin a cat. I’m not sure why you’d want to skin a cat, but if you find yourself in that situation, you should use a cat-skinning knife, rather than a spoon or chainsaw (sorry). Let’s apply that same logic to manufacturing methods. Here are some of the most common manufacturing methods, their (dis)advantages, and relative costs.
Casting/molding
铸造涉及液体浇注或将热材料注入模具中。该过程通常用于制造非常复杂的形状。铸造造成“粗糙”的形状，是一个有点不精确的过程。但是，没关系，因为并不总是需要精确度。铸造是一种多功能工艺，可以生产许多不同的材料，从金属到塑料。这种方法非常受欢迎，并被从汽车外壳（传输，发动机等）到玩具。模具及其相关的工具昂贵且复杂;它们通常是实现许多通用的最佳方法，具有较大的体积/表面积比。
钣金
钣金forming, a sub-process of cold-forming (as opposed to the hot-forming of casting) is a process used to create thin metal enclosures that don’t need to be pretty or watertight. For thin, complex shapes, forming makes more sense than casting because of the difficulty of forcing a molten material around tight corners and into long, thin channels. It also takes much less energy to deform a thin piece of metal than it does to melt the metal into a liquid state. Stamping is a forming process that uses dies under massive load to crush metal into a desired shape, and is extremely common for automotive outer parts (hood, door panels, etc.). Electrical boxes are made by stamping a blanket sheet to add cuts and holes, and then bending to form the box into its final shape.
Machining
加工，无论是CNC还是手动，都是从物体中除去材料的过程，通常具有旋转刀具或钻头。加工过程可以实现极端精度，并且通常用于放置精确的孔并进行平滑，平面平面。a的轴（没有伐木工人）CNC machine，它具有的多功能性。加工是一种昂贵的过程，只能在任何其他方式无法实现特征的必要精度（位置，尺寸，表面光洁度）时使用。beplay sports 是另一种加工方法，可通过电气放电去除材料（火花）。对于极小的细腻的功能，切割工具难以实现。但是，EDM也缓慢而昂贵。
2D cutting
Plasma, lasers, drills, and even water can be used to precisely cut 2D shapes out of flat sheets of material. This method shines when precise and/or deep cuts are needed. Like machining, 2D cutting provides great results but is but slower and more expensive than stamping.
3D打印
3D打印is the futuristic holy grail of manufacturing. Also known as additive manufacturing, this method is prized for its ease of use and versatility in creating impossibly complex shapes with remarkable precision. Internal cooling channels, undercuts, and an Eiffel tower that fits on your hand are all commonplace and easy to make. 3D printing is extremely useful for quick prototypes. While 3D printing is relatively slow and expensive in manufacturing, it is currently being investigated and adopted by companies for mass production.
Plastic thermoforming
As an analogy to metal processes, plastic thermoforming falls somewhere between casting and cold-forming. (Note: The word “Plastic” can refer to a specific material, or be a synonym for “permanent”, ie. plastic deformation = permanent deformation. In this case, we are referring to permanent deformation of plastic material). A thin sheet of material is heated and then formed to a one-sided mold to create a basic shape. Tooling cost is lower than注塑成型但是该过程更加费力，使得较低批量生产良好。
Tolerances
这些天，宽容是一种美德;不容忍不会容忍！Tolerance是指允许偏离理想ate. In manufacturing, the less tolerant you are, the more precise your manufacturing must be, and thus more expensive. This is central to choosing your method of manufacturing. For example, imagine that we must mount two objects together using bolts. The location, size, and direction of the bolt holes are all important, as is the parallelism of the two mounting faces. GD&T (geometric dimensioning and tolerancing) is a field dedicated to establishing quantifiable geometric constraints on 3D features. Tolerances should be back-calculated as the greatest allowable deviation, while still maintaining function (plus some safety factor). There are various tricks you can use to make manufacturing easier and cheaper (they’d literally throw gearboxes together, if they could) while still maintaining functionality. For example, “bonus tolerances” allow greater deviations in one aspect if a corresponding relevant variable is adjusted (for bolt thru-holes, positional misalignment can increase if hole size increases as well).
做
在Shia Labeouf的明智之文中，“不要让你的梦想成为梦想。”您正在尝试促进您的Brainchild，并且具有成本效益的制造是您必须通过的最终痛苦的香肠，如果我们希望您的想法留在一天的光明。一般来说，我们应该使用制造限制来指导我们的设计决策 - 即，如果您想保存$$$并致富。你想富有，对吗？然后用您的同事分享这篇文章，并帮助您的工程师设计，并考虑到制造效率。
